1. Field of the Invention
The present invention relates to tools for securing a work piece in a fixed position. More particularly, the invention provides a tool for immobilizing camshafts bearing drive gears against rotation by interfering with the gears.
2. Description of the Prior Art
When internal combustion engines having reciprocating pistons are disassembled for service, certain components must be correctly positioned to assure operability. Notably, camshafts must be positioned in a specific, predetermined angular or rotational position relative to the crankshaft, or opening and closing of the poppet valves will be other than to the manufacturer's specifications. Camshafts are typically marked to enable visual confirmation that they are properly oriented by notches or the like formed in their drive gears. It would be possible to disturb the original orientation of camshafts and to subsequently re-establish proper orientation prior to final assembly of the engine.
However, it may prove expedient to immobilize one or more camshafts in their appropriate positions if the work being performed does not require movement of the camshafts. A device for preventing rotation of a camshaft is shown in U.S. Pat No. 5,099,563, issued to Wolfgang Strusch on Mar. 31, 1992. The invention of Strusch essentially provides pins projecting against the camshaft itself. By contrast, the present invention is configured to interfere with the teeth of the gear or sprocket turning the camshaft by a chain or belt.
The structure of the present invention comprises two tongues projecting almost perpendicularly from a flat base. This construction is somewhat suggested by the configuration of the subject device of U.S. Pat. No. 5,297,339, issued to Todd A.
Morgenstern et al. on Mar. 29, 1994. However, dimensions and proportions of the device of Morgenstern et al. is unwieldy if not entirely unworkable in the environment of the present invention.
U.S. Pat. No. 5,401,011, issued to Alan D. Gatenby et al. on Mar. 28, 1995, shows a device suitable for immobilizing a drive belt by pinching the same as the belt engages two spaced apart pulleys. By contrast, the present invention does not engage a chain or belt, engaging instead teeth of two adjacent sprockets or gears.
U.S. Pat. No. 5,454,153, issued to Hector Noel on Oct. 3, 1995, shows a work piece holder having two pegs projecting perpendicularly from a flat base, parallel to one another and adjustably spaced apart. Despite sharing structural similarities with the novel tool, Noel's device cannot function as does the novel tool.
None of the above inventions and patents, taken either singly or in combination, is seen to describe the instant invention as claimed.